Related papers: Enhanced Neutrino Cooling from Parity-Doubled Nucl…
In confined hadronic matter, the spontaneous breaking and restoration of chiral symmetry can be described by considering nucleons, $N_{+}(939)$, and excited states of opposite parity, $N_{-}(1535)$. In a cold, dense hadronic phase where…
We study different stages of the neutron star cooling by computing neutron star properties at various temperatures and entropies using an effective chiral model including hadronic and quark degrees of freedom. Macroscopic properties of the…
The parity doublet model, containing the SU(2) multiplets including the baryons identified as the chiral partners of the nucleons is applied to neutron stars. The maximum mass for the star is calculated for different stages of the cooling…
We study the heat capacity and neutrino emission reactions (direct and modified Urca processes, nucleon-nucleon bremsstrahlung, Cooper pairing of nucleons) in matter of supranuclear density of the neutron star cores with superfluid neutrons…
The implications of hyperon pairing for the thermal evolution of neutron stars containing hyperons are investigated. The outcome of cooling simulations are compared for neutron star models composed only of nucleons and leptons, models…
After a brief summary of neutron star cooling theory I present results which emphasize the importance of baryon pairing in the neutron star core. I show how the thermal evolution may be totally controlled by pairing for models which include…
We simulate cooling of superfluid neutron stars with nucleon cores where direct Urca process is forbidden. We adopt density dependent critical temperatures $T_{cp}(\rho)$ and $T_{cn}(\rho)$ of singlet-state proton and triplet-state neutron…
We present a phenomenological model to investigate the chiral phase transition characterized by parity doubling in dense, beta equilibrated, cold matter. Our model incorporates effective interactions constrained by SU(3) relations and…
We apply an extended version of the SU(3) parity model, containing quark degrees of freedom, to study neutron stars. The model successfully reproduces the main thermodynamic features of QCD which allows us to describe the composition of…
It is expected that nucleons and their parity partners become degenerate when chiral symmetry is restored. We investigate this question in the context of the thermal transition from the hadronic phase to the quark-gluon plasma, using…
Neutrino emission from the dense hadronic component in neutron stars is subject to strong modifications due to collective effects in the nuclear medium. We implement new estimates of the neutrino emissivities of two processes operating in…
Observation of cooling neutron stars can potentially provide information about the states of matter at supernuclear densities. We review physical properties important for cooling such as neutrino emission processes and superfluidity in the…
The Parity doublet model containing the SU(2) multiplets including the baryons identified as the chiral partners of the nucleons is applied for neutron star matter. The chiral restoration is analyzed and the maximum mass of the star is…
The thermal evolution of isothermal neutron stars is studied with matter both in the hadronic phase as well as in the mixed phase of hadronic matter and strange quark matter. In our models, the dominant early-stage cooling process is…
We investigate the properties of dense matter and neutron stars. In particular we discuss model calculations based on the parity doublet picture of hadronic chiral symmetry. In this ansatz the onset of chiral symmetry restoration is…
We study the thermal evolution of neutron stars in the presence of hyperons or kaons in the core. Our results indicate that the nucleon and hyperon direct Urca processes play crucial roles for the cooling of neutron stars. The presence of…
We model neutron star cooling with several microscopic nuclear equations of state based on different nucleon-nucleon interactions and three-body forces, and compatible with the recent GW170817 neutron star merger event. They all feature…
I give a general overview of the theory of neutron star cooling, emphasizing the intuitive understanding of the effects of the various physical ingredients, including the recently proposed accreted envelopes and neutrino emission from…
We review the chiral variant and invariant components of nucleon masses and its consequence on the chiral restoration in extreme conditions, neutron star matter in particular. We consider a model of linear realization of chiral symmetry…
We study thermal evolution of isolated neutron stars in scalar-tensor theories for the first time. Whether the rapid cooling due to the direct Urca process occurs or not is an interesting question in the viewpoint of the temperature…